// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_FILTERS_FFMPEG_AAC_BITSTREAM_CONVERTER_H_
#define MEDIA_FILTERS_FFMPEG_AAC_BITSTREAM_CONVERTER_H_

#include <stdint.h>

#include "base/macros.h"

#include "media/base/media_export.h"
#include "media/filters/ffmpeg_bitstream_converter.h"

// Forward declarations for FFmpeg datatypes used.
struct AVCodecContext;
struct AVPacket;

namespace media {

// Bitstream converter that adds ADTS headers to AAC frames.
class MEDIA_EXPORT FFmpegAACBitstreamConverter
    : public FFmpegBitstreamConverter {
public:
    enum { kAdtsHeaderSize = 7 };

    // The |stream_codec_parameters| will be used during conversion and should be
    // the AVCodecParameters for the stream sourcing these packets. A reference to
    // |stream_codec_parameters| is retained, so it must outlive this class.
    explicit FFmpegAACBitstreamConverter(AVCodecContext* stream_codec_parameters);
    ~FFmpegAACBitstreamConverter() override;

    // FFmpegBitstreamConverter implementation.
    // Uses FFmpeg allocation methods for buffer allocation to ensure
    // compatibility with FFmpeg's memory management.
    bool ConvertPacket(AVPacket* packet) override;

private:
    // Variable to hold a pointer to memory where we can access the global
    // data from the FFmpeg file format's global headers.
    AVCodecContext* stream_codec_parameters_;

    bool header_generated_;
    uint8_t hdr_[kAdtsHeaderSize];
    int codec_;
    int audio_profile_;
    int sample_rate_index_;
    int channel_configuration_;
    int frame_length_;

    DISALLOW_COPY_AND_ASSIGN(FFmpegAACBitstreamConverter);
};

} // namespace media

#endif // MEDIA_FILTERS_FFMPEG_AAC_BITSTREAM_CONVERTER_H_
